Added a command to list schematics and the abilitiy to autodetect schematic format

src/main/java/com/sk89q/worldedit/schematic/MCEditSchematicFormat.java

@@ -22,6 +22,7 @@ import com.sk89q.jnbt.ByteArrayTag;
 import com.sk89q.jnbt.CompoundTag;
 import com.sk89q.jnbt.IntTag;
 import com.sk89q.jnbt.ListTag;
+import com.sk89q.jnbt.NBTConstants;
 import com.sk89q.jnbt.NBTInputStream;
 import com.sk89q.jnbt.NBTOutputStream;
 import com.sk89q.jnbt.ShortTag;
@@ -34,6 +35,7 @@ import com.sk89q.worldedit.blocks.BaseBlock;
 import com.sk89q.worldedit.blocks.TileEntityBlock;
 import com.sk89q.worldedit.data.DataException;
 
+import java.io.DataInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
@@ -244,6 +246,31 @@ public class MCEditSchematicFormat extends SchematicFormat {
         stream.close();
     }
 
+    @Override
+    public boolean isOfFormat(File file) {
+        DataInputStream str = null;
+        try {
+            str = new DataInputStream(new GZIPInputStream(new FileInputStream(file)));
+            if ((str.readByte() & 0xFF) != NBTConstants.TYPE_COMPOUND) {
+                return false;
+            }
+            byte[] nameBytes = new byte[str.readShort() & 0xFFFF];
+            str.readFully(nameBytes);
+            String name = new String(nameBytes, NBTConstants.CHARSET);
+            return name.equals("Schematic");
+        } catch (IOException e) {
+            return false;
+        } finally {
+            if (str != null) {
+                try {
+                    str.close();
+                } catch (IOException ignore) {
+                    // blargh
+                }
+            }
+        }
+    }
+
     /**
      * Get child tag of a NBT structure.
      *

src/main/java/com/sk89q/worldedit/schematic/SchematicFormat.java

@@ -45,6 +45,8 @@ import java.util.Set;
  */
 public abstract class SchematicFormat {
     private static final Map<String, SchematicFormat> SCHEMATIC_FORMATS = new HashMap<String, SchematicFormat>();
+
+    // Built-in schematic formats
     public static final SchematicFormat MCEDIT = new MCEditSchematicFormat();
 
     public static Set<SchematicFormat> getFormats() {
@@ -55,6 +57,19 @@ public abstract class SchematicFormat {
         return SCHEMATIC_FORMATS.get(lookupName.toLowerCase());
     }
 
+    public static SchematicFormat getFormat(File file) {
+        if (!file.isFile()) {
+            return null;
+        }
+
+        for (SchematicFormat format : SCHEMATIC_FORMATS.values()) {
+            if (format.isOfFormat(file)) {
+                return format;
+            }
+        }
+        return null;
+    }
+
     private final String name;
     private final String[] lookupNames;
 
@@ -137,4 +152,6 @@ public abstract class SchematicFormat {
      * @throws DataException If the clipboard has data which cannot be stored
      */
     public abstract void save(CuboidClipboard clipboard, File file) throws IOException, DataException;
+
+    public abstract boolean isOfFormat(File file);
 }